Charles Sacleux was born in 1856 and died in 1943. He was a French Catholic missionary and served in the Holy Spirit mission in Zanzibar. He was “regarded as the greatest of Swahili lexicographers, [as] he was the first to write on the Swahili language”.[1] Sacleux’s writings are also valuable because he studied Swahili before it was standardized and before the influence of the English language.[2] Sacleux published two major Swahili dictionaries in the early 20th century: Grammaire des dialectes swahilis, published in 1909, and Dictionnaire swahili-francais, published in 1939.
Sacleux was ordained a Catholic priest in 1877, joined the Congregation of the Holy Spirit in 1878, and arrived in Zanzibar in 1879 as a Catholic missionary. Sacleux spent years preparing and editing a Swahili dictionary, and after he returned to Europe, he “devoted the rest of his long life to work on Swahili dialects.”[3]
Sacleux was a committed botanist and spent a lot of his time studying the plants in Africa. In his Swahili dictionary, he includes many plants and animals.
[2] https://www.oxforddnb.com/display/10.1093/ref:odnb/9780198614128.001.0001/odnb-9780198614128-e-50446
[3] Alain Richard, Charles Sacleux (1856-1943), founder of Swahili studies in France, (Christian History and Missions, 2007, 4.4), pages 105 to 114. https://shs.cairn.info/revue-histoire-monde-et-cultures-religieuses1-2007-4-page-105?lang=fr&ref=doi